RD Artar coverage at infinity

[Jarin Blaschke]

Hi all:

I’m getting inconsistent claims via searching, so I thought I’d just ask here:

Will a 24” Red Dot Artar cover 12x20” at infinity? What exactly is the image circle at infinity?

Overall, I’m looking for high performing options in the 450 to 600mm range for 12x20. Finding a XXL 550 is tough!

-Jarin

 

[Dan Fromm]

See http://web.archive.org/web/20170606145746/http://www.pacificrimcamera.com/rl/00268/00268.pdf

Coverage at infinity is half coverage at 1:1. It won't cover 12x20. I don't believe any 600 +/- mm process lens will cover 12x20 (diagonal nearly 600 mm) at infinity. They're all narrow angle lenses. f/6.3 Tessars and tessar types with that focal length will do.

Happy hunting,

 

[Jarin Blaschke]

Thanks - I was afraid so. So far it seems the options are:

Schneider XXL 550
(Very hard to track down, expensive)

Fujinon C 600
(Narrowly covers at inf)

Fujinon A 600
(Better coverage than the C, but nearly as expensive as the XXL)

Dagor 19” (and 24”?)
(I’ve only seen these as 80+ year old lenses, and uncoated, perhaps not the best performance. Were these made in the MC era?)

Am I missing anything?
I am looking for high performance corner-to-corner at apertures in the /32 to /45 realm, and would like to future-proof for up to 4x enlargement.

Jarin

 

[Dan Fromm]

Dagors will do, are scarce. Goerz Ameican Optical Company, not to be confused with American Optical Company, made coated Dagors after WW II. When Schneider acquired Goerz American, Dagor production was shifted to Kern, in Switzerland. Very late Dagors might be MC. Might. Remember that Dagors and similar 6/2 double anastigmats have only 4 air-glass surfaces so benefit little from coating, even less from multicoating. The very scarce 355/6.8 Boyer Beryl is a dagor type. So are Berthiot Eurygraphes, made in a wide range of focal lengths. Again, scarce.

Long Tessars and tessar types are more common. Think of the 500/6.3 Krauss Zeiss Tessar, these pop up from time to time.

Until you do your homework properly you're going to miss many opportunities.

What do you plan to do for shutters?

 

[Jarin Blaschke]

Dagors will do, are scarce. Goerz Ameican Optical Company, not to be confused with American Optical Company, made coated Dagors after WW II. When Schneider acquired Goerz American, Dagor production was shifted to Kern, in Switzerland. Very late Dagors might be MC. Might. Remember that Dagors and similar 6/2 double anastigmats have only 4 air-glass surfaces so benefit little from coating, even less from multicoating. The very scarce 355/6.8 Boyer Beryl is a dagor type. So are Berthiot Eurygraphes, made in a wide range of focal lengths. Again, scarce.

Long Tessars and tessar types are more common. Think of the 500/6.3 Krauss Zeiss Tessar, these pop up from time to time.

Until you do your homework properly you're going to miss many opportunities.

What do you plan to do for shutters?

Well I’m trying to do my homework. Weirdly the LF Forum never gave me an account where I can post and they’ve never responded to my inquiries.

Did the Dagor cease to be made in 19”+ focal lengths before the more common ones? I’ve only seen these longer ones as rather old, pre-WW2 examples so far.

Aside from The Nikkor M, which seems to ceiling at 450mm, I’m still ignorant to other Tessar types. Eager to learn. What types are the Fujinons? I assume the XXL is a Plasmat?

If I don’t get a copy lens, it seems shutters are out there.

Jarin

 

[Dan Fromm]

Well, if you're eager to learn, go to https://www.largeformatphotography.info/forum/. The lenses subforum has a sticky "Where to look ..." The first post in that discussion has a link to a pdf list of links that you should find interesting and educational. Go for it.

About shutters. Yes, there are shutters out there. Whether there are shutters for any old lens in barrel is another matter, especially if the lens has a long focal length.

 

[DMS206]

I have used a12x20 with a 16-1/2” red dot artar with good results, however for contact prints only, also a 20” f7 orbit ilex, and a 480mm apo ronar, which is the sharpest of the three.